To explore the dry-wet durability of solidified sludge in the application of landfill cover, solidification strength tests of soda residue-slag-lime were performed under the condition of dry-wet cycles. The results show that the hydration reaction continues with the increase of dry-wet cycles, leading to increasing amount of hydration products including ettringite, hydro aluminite and calcium silicate hydrate, decreasing pore volume, and dense microstructure. In general, the unconfined compressive strength has an increase trend with the dry-wet cycles. The strength after the seventh dry-wet cycle is 1.16 to 1.45 times of that before the cycles. From the perspective of microstructure and unconfined compressive strength, sludge solidified with soda residue-slag-lime has good durability under dry-wet cycles. Keywords: soda residue; solidified sludge; dry-wet cycle; unconfined compressive strength; dry-wet durability; microstructure 〖FL